john-Avignon worked well for us, but it's good to be strategic as far as parking and entry/exit to the city. We selected a B & B based partly on its convenience to the public parking outside the city wall. You don't want to drive in Avignon, we had a ten minute walk from our lodging to the car park, which was free, and we did not have a problem at all. Once you are out of Avignon in the morning rush you can move along pretty well. All in all, we liked the larger size and numerous sights/shops/food ops in Avignon. Arles would be nice too, I'm sure, though you do need parking with your Air BnB/lodging, I understand. There are a few different public lots outside the wall at Avignon.
We really liked Les Halles in Avignon, the indoor public market. A modest breakfast followed by a visit to the public market around lunch time worked well. Oysters, fresh from Brittany, are over in the corner, be sure to track them down if you are a fan.
From Avignon (four nights) we day-tripped to the Pont du Gard, Nimes, Roussillon, Gordes, Les Baux and the Carriere de Lumieres (not to be missed, imho), Isle sur la Sorgue, and just cruised the back roads enjoying the area. It's pretty central, and has enough size to be entertaining on its own. Aix en Provence is often derided for traffic issues, and being a bit of a college town, though I have not been. After reading up a bit on Aix v Avignon, we chose the latter.
It would be useful for you to track down the market days for each of the areas you want to see; both for gathering provisions and perhaps for avoiding on market day due to traffic and crowds, though you gain some cushion being there in October.
Cheers, and enjoy your trip!